1. Field of the Invention
The present invention relates to user authentication, and more particularly, to user authentication adopting a combination of password authentication and biometrics.
2. Description of the Related Art
Hereinafter, conventional user authentication techniques adopting a combination of password authentication and biometrics will be described in the following paragraphs.
Korean Patent Application No. 2000-19152 entitled “Portable Security Authentication Apparatus and System and Operating Method Thereof” discloses a user authentication method based on a sequential combination of biometrics, such as fingerprint or voice recognition, and password authentication.
Korean Patent Application No. 2000-3099 entitled “Door Lock/Unlock System Adopting Combination of Fingerprint Authentication and Password Authentication and Method of Controlling the Same” discloses a user authentication technique in which a user whose fingerprint cannot be registered and a visitor whose fingerprint has not yet been registered can be authenticated by inputting a password.
Korean Patent Application No. 2000-60312 entitled “Entrance/Exit Control System and Method Adopting Fingerprint and Face Recognition” discloses a user authentication technique in which a user can be authenticated through a combination of fingerprint and face recognition or through a combination of password authentication, and fingerprint and face recognition. In this user authentication technique, security can be guaranteed by storing a fingerprint and face image of an unauthenticated person.
Korean Patent Application Nos. 2001-15559 and 1999-26726 disclose a door opening and shutting system based on fingerprint recognition and a method of recognizing a password of a mobile phone through voice recognition, respectively.
The above-described conventional user authentication techniques carry out a plurality of user authentication processes based on a simple combination of a password and biometrics information or a simple combination of a security key and biometrics information.
The performance of a conventional biometrics device that authenticates a user using, for example, a face, a fingerprint, and/or an iris, as an authentication key may be deteriorated because the authentication key is likely to be input into the conventional biometrics device differently all the time depending on where and how a user uses the conventional biometrics device, or because the authentication key is also likely to vary itself according to the passage of time.
In the case of using a key, a password, an integrated circuit (IC) card, or a radio frequency (RF) card, an authentication result represented by a binary code “0” or “1” is obtained in response to the reception of an authentication key. On the other hand, in the case of using a biometrics device, an authentication result can be represented by a value between “0” and “1” depending on the performance of an authentication device and the extent to which an input authentication key matches with registered data. Therefore, there is a need to additionally set an authentication threshold value for differentiating a refusal (0) from an authentication (1). If the authentication threshold value is set high, the possibility of a non-registered person being accepted decreases, but the possibility of a registered person being rejected increases. Therefore, the registered person may not be authenticated, which is called a false rejection (FR), or the non-registered person may be authenticated instead, which is called a false acceptance (FA).